The 3D Printing of Biomass–Fungi Composites: Effects of Waiting Time after Mixture Preparation on Mechanical Properties, Rheological Properties, Minimum Extrusion Pressure, and Print Quality of the Prepared Mixture

Abstract

Biomass–fungi composites, an emerging class of sustainable materials, have potential applications in the construction and packaging industries. Molding-based manufacturing methods are typically employed to make products from these composites. Recently, a 3D printing-based method was developed for biomass–fungi composites to eliminate the need for making molds and to facilitate customized product design compared with manufacturing methods based on molding and hot-pressing. This method has six stages: biomass–fungi material preparation; primary colonization; mixture preparation; printing; secondary colonization; and drying. This paper reports a study about the effects of waiting time between the mixture preparation and 3D printing using biomass–fungi composites. As the waiting time increased from 0.25 to 3 h, the hardness and compressibility of the prepared mixture increased. As the waiting time increased from 0.25 to 8 h, the shear viscosity showed a decreasing trend; the yield stress of the prepared mixture increased at the beginning, then significantly decreased until the waiting time reached 3 h, and then did not significantly vary after 3 h. As the waiting time increased, the storage modulus and loss modulus decreased, the loss tangent delta increased, and the minimum required printing pressure for continuous extrusion during extrusion-based 3D printing increased. The print quality (in terms of layer-height shrinkage and filament-width uniformity) was reasonably good when the waiting time did not exceed 4.5 h.

3D bioprinting of microorganisms: principles and applications

“…Fungal composites bioink in 3D bioprinting can offer novel topics of research for more sustainable materials and production methods in industries like construction and packaging, replacing traditional materials such as plastics and cements [ 125 ]. Fungi poses a high concentration of chitin, an abundant biomolecule with similar properties to cellulose.…”

“…This creates a final product with similar characteristics to wood or cork. One of the advantages is using very low-cost raw materials from agricultural waste sources such as corn stover and rice straw as candidates to grow fungi biomass, which transforms these raw materials into a network of hyphae [ 125 ]. The process consists of 6 stages: (1) the recollection of biomass and fungi from the basidiomycete group, (2) colonization of the material, (3) mixing, (4) 3D bioprinting, (5) secondary colonization and (6) finally drying.…”

Towards the microbial home: An overview of developments in next‐generation sustainable architecture

“…sugarcane bagasse, rice husks, cotton stalks and straw) to make a single, solid material called a mycelium biocomposite (Fairus et al, 2022 ; Sydor et al, 2022 ) (Figure 1 ). Part organic block, part fungal matrix, these versatile materials can be moulded, or 3D printed (Rahman et al, 2022 ), into a wide range of forms to become insulating bricks and even patchwork ‘tapestries’ of recycled materials—which keep our homes warm and insulate them against unwanted noise (Robertson et al, 2020 ; Yang et al, 2021 ).…”

Three-Dimensional Printing of Biomass–Fungi Biocomposite Materials: The Effects of Mixing and Printing Parameters on Fungal Growth

“…Furthermore, this approach reduces manufacturing waste [19]. The six stages of this extrusion-based 3D printing method are discussed elaborately in previously published papers [5,20,21].…”

“…The authors also investigated the effects of mixture composition on rheological properties of biomassfungi mixtures prepared for 3D printing [20]. Additionally, they investigated the effects of waiting time (between the time the mixture was prepared and the time of 3D printing using the mixture) on the mechanical properties and rheological properties of the biomass-fungi mixtures, as well as the minimum printing pressure required for continuous extrusion during 3D printing, and the quality of the printed samples (characterized by layer height shrinkage and filament width uniformity) [21].…”